#include <sys/types.h>
#include <sys/socket.h>
#include <netdb.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>

#define BUF_SIZE 500

        int
main(int argc, char *argv[])
{
        struct addrinfo hints;
        struct addrinfo *result, *rp;
        int sfd, s, j;
        size_t len;
        ssize_t nread;
        char buf[BUF_SIZE];

        if (argc < 3) {
                fprintf(stderr, "Usage: %s host port msg...\n", argv[0]);
                exit(EXIT_FAILURE);
        }

        /* Obtain address(es) matching host/port */

        memset(&hints, 0, sizeof(struct addrinfo));
        hints.ai_family = AF_UNSPEC;    /* Allow IPv4 or IPv6 */
        hints.ai_socktype = SOCK_DGRAM; /* Datagram socket */
        hints.ai_flags = 0;
        hints.ai_protocol = 0;          /* Any protocol */

        s = getaddrinfo(argv[1], argv[2], &hints, &result);
        if (s != 0) {
                fprintf(stderr, "getaddrinfo: %s\n", gai_strerror(s));
                exit(EXIT_FAILURE);
        }

        /* getaddrinfo() returns a list of address structures.
           Try each address until we successfully connect(2).
           If socket(2) (or connect(2)) fails, we (close the socket
           and) try the next address. */

        for (rp = result; rp != NULL; rp = rp->ai_next) {
                sfd = socket(rp->ai_family, rp->ai_socktype,
                                rp->ai_protocol);
                if (sfd == -1)
                        continue;

                if (connect(sfd, rp->ai_addr, rp->ai_addrlen) != -1)
                        break;                  /* Success */

                close(sfd);
        }

        if (rp == NULL) {               /* No address succeeded */
                fprintf(stderr, "Could not connect\n");
                exit(EXIT_FAILURE);
        }

        freeaddrinfo(result);           /* No longer needed */

        /* Send remaining command-line arguments as separate
           datagrams, and read responses from server */

        for (j = 3; j < argc; j++) {
                len = strlen(argv[j]) + 1;
                /* +1 for terminating null byte */

                if (len + 1 > BUF_SIZE) {
                        fprintf(stderr,
                                        "Ignoring long message in argument %d\n", j);
                        continue;
                }

                if (write(sfd, argv[j], len) != len) {
                        fprintf(stderr, "partial/failed write\n");
                        exit(EXIT_FAILURE);
                }

                nread = read(sfd, buf, BUF_SIZE);
                if (nread == -1) {
                        perror("read");
                        exit(EXIT_FAILURE);
                }

                printf("Received %ld bytes: %s\n", (long) nread, buf);
        }

        exit(EXIT_SUCCESS);
}

